Abstract: Objective To investigate the role that Notch1-Dll4 signal pathway played in the oxygen-induced retinal neovascularization of mice by analyzing the expression of Dll4,VEGFR-1,and VEGFR-2 in retinal neovascularization. Methods Thirty 7-day-old C57BL/6J mice were divided into oxygen-induced retinopathy group and control group.In oxygen-induced retinopathy group,15 mice were exposed to (75±2) % oxygen for 5 days and then back to room air.In control group,15 mice were raised in room air.5 mice were taken from each group at p7(postnatal seventh day),p12 and p17 respectively,and then enucleated the eyeballs to detect the Dll4,VEGFR-1 and VEGFR-2 by immunohistochemistry. Results There were Dll4,VEGFR-1 and VEGFR-2 positive cells in the retina of both groups.The positive rate of VEGFR-1 had no difference between two groups in p7 and p12 (P＞0.05).While in p17,the positive rate of VEGFR-1 in oxygen-induced retinopathy group was lower than that in control group(P<0.05).The positive rate of VEGFR-2 had no difference between two groups in p7,p12,p17(P＞0.05).The positive rate of Dll4 had of no difference between these two groups in p7(P＞0.05),and in p12 and p17,the positive rate of Dll4 in oxygen-induced retinopathy group was lower than that in control group (P₁₂＜0.05,P₁₇＜0.001).In oxygen-induced retinopathy group,the positive rate of VEGFR-1 and Dll4 decreased from p7 to p17(P＜0.001,P＜0.001),and that of VEGFR-2 increased from p7 to p17 (P＜0.05).In control group,the positive rate of VEGFR-1 showed a decreased tendency at different timing(P＜0.05=0.017),and that of VEGFR-2 increased at different timing(P＜0.001),while that of Dll4 didn't changed obviously(P＞0.05). Conclusion Notch1 - Dll4 signaling pathway may be involved in the regulation of VEGF in the process of retinal angiogenesis.The expression of Dll4 is inhibited in oxygen-induced retinopathy mice during the formation of neovascularization,so it failed to show negative feedback regulation to VEGF; The expression of VEGFR-1 is inhibited in oxygen-induced retinopathy mice and has a consistent trend with Dll4.

Key words: delta-like ligand 4, vascular endothelial growth factor, retinopathy of prematurity:neovascularization, animal model

摘要： 目的 分析Delta 样配体4、血管内皮细胞生长因子受体1、血管内皮细胞生长因子受体2在视网膜新生血管中的表达,探讨Notch1-Dll4信号通路在氧诱导视网膜病小鼠新生血管形成中的作用。方法 选用鼠龄7 d的C57BL/6J新生鼠30只,分成实验组和对照组。实验组15只,在氧浓度为(75±2)%的密闭容器中生长5 d,回到室内正常空气中;对照组15只,在室内正常空气中生长。两组各取p7(生后7 d)、p12、p17新生鼠 5只,摘除眼球,免疫组化法进行Dll4、 VEGFR-1、 VEGFR-2的测定。结果 免疫组化结果显示,对照组和实验组Dll4与VEGFR-1、VEGFR-2在视网膜均可见阳性细胞表达,p7和p12时,两组间VEGFR-1细胞的阳性率差异无统计学意义(P＞0.05);而在p17时,两组间VEGFR-1细胞的阳性率有差异,实验组低于对照组(P＜0.05);p7、p12和p17时,两组间VEGFR-2细胞的阳性率差异均无统计学意义(P＞0.05);p7时,两组间Dll4细胞的阳性率差异无统计学意义(P＞0.05);而在p12和p17时,两组间Dll4细胞的阳性率差异有统计学意义(P₁₂＜0.05,P₁₇＜0.001),实验组的阳性率低于对照组;实验组不同时间点VEGFR-1和Dll4的阳性细胞率均有降低趋势(P均＜0.001),VEGFR-2阳性细胞率有增高趋势(P＜0.05)。对照组不同时间点VEGFR-1的阳性细胞率有降低趋势(P＜0.05),不同时间点VEGFR-2的阳性细胞率有增高趋势(P＜0.001),不同时间点Dll4的阳性细胞率没有变化趋势(P＞0.05)。结论 Notch1-Dll4信号通路可能参与了 VEGF 调控视网膜新生血管生成的过程,Dll4在氧诱导视网膜病小鼠新生血管的形成中表达受到抑制,对VEGF未能进行有效负反馈调控;VEGFR-1的表达受到抑制,且与Dll4表达趋势变化一致。

关键词: Delta样配体4, 血管内皮细胞生长因子受体, 早产儿视网膜病, 新生血管, 动物模型